In order to store electric energy for subsequent discharge, batteries or accumulators are used. They enable power to be supplied independently of power supply networks or electric generators. Batteries can also be used to supply electric loads in aircraft.
For general use outside aircraft, composite batteries are known and, in their basic form, these have three layers. In this case, a separating layer is arranged between a cathode layer and an anode layer. The cathode layer and the anode layer can comprise a polymer, which is reinforced by carbon fibres. In this case, the fibres of the cathode layer can be coated, e.g. with iron oxide. The separating layer can be composed of a polymer with a reinforcement consisting of glass fibres. The separating layer acts as an electric insulator for electrons. In this case, lithium ions can pass through the separating layer but electrons cannot. Since the lithium ions are inflammable, the use of lithium ion batteries or accumulators in aircraft is critical since aircraft have only limited extinguishing capacities.
In this context, DE 10 2010 041387 A1 or EP 3 053 206 B1, for example, disclose the use of flame retardants in the housing of unstructured lithium ion batteries. However, the lithium ion batteries may start to burn within the housing since it is only at the housing of the battery that a fire comes into contact with the flame retardant, that is to say that the housing of the battery may reach high temperatures owing to the flames. This can damage the surroundings of the housing and, in the worst case, can lead to ignition of the materials surrounding the housing.